JP5714335B2 - Steel cord manufacturing apparatus and manufacturing method - Google Patents

Description

  The present invention relates to an apparatus and a method for manufacturing a steel cord for reinforcing rubber articles. Specifically, the present invention relates to a manufacturing apparatus and a manufacturing method of a steel cord for reinforcing rubber articles that can suppress swelling of an outermost filament of a stranded wire.

  Steel cords for reinforcing rubber articles used for tires and the like are manufactured by twisting a plurality of steel filaments (element wires) with a twisting machine. Examples of the twisting machine used for manufacturing the steel cord for reinforcing rubber articles include a tubular twisting machine and a buncher twisting machine. Among these, the buncher-type stranded wire machine has higher production efficiency than the tubular-type stranded wire machine, and therefore, the buncher-type stranded wire machine is superior from the viewpoint of productivity of the steel cord for reinforcing rubber articles.

  However, a steel cord for reinforcing rubber articles manufactured by a buncher type stranding machine has a core layer made of one or more filaments and one or more layers made of a plurality of filaments formed around the core layer. When wrapping a wrapping filament around a steel cord twisted with the sheath layer of the layer, or when twisting a plurality of steel cords to form a double twisted cord, the obtained steel cord is laddered by a guide pulley, etc. In some cases, the outermost filament swells and a twist failure occurs.

  This is to suppress the torsion of the steel cord, and an over twister is provided in the twisting machine, and the twisted steel cord is twisted to the extent that the torsion occurs to form the outermost filament. The rate also increased at the same time, which was caused by the larger diameter of the steel cord.

  Regarding the processing to be applied to the steel cord after the stranded wire provided in the twisting machine, it has been proposed that the obtained twisted cord is repeatedly bent by a straightening roll group in which the rolls are arranged in a staggered pattern. (Patent Document 1).

JP 2009-249757 A

  In Patent Document 1, it is said that a steel cord excellent in straightness can be obtained by repeatedly bending a twisted cord with a correction roll group in which rolls are arranged in a staggered pattern. However, it is not sufficient to suppress the bulging of the outermost filament only by repeatedly bending the stranded wire with the straightening roll group, and there is room for improvement in the manufacturing technique of the steel cord.

  The present invention advantageously solves the above-described problem, and a steel cord manufacturing apparatus that can advantageously suppress twisting failure due to bulging of the outermost filament of a steel cord manufactured using a buncher-type twisted wire machine. And it aims at providing a manufacturing method.

The steel cord manufacturing apparatus of the present invention includes a buncher type twisted wire machine that manufactures a twisted wire by twisting a plurality of strands or cords,
An over twister that twists the stranded wire produced by this buncher type stranding machine;
And have your downstream movement path of the stranded wire produced by the buncher type stranding machine provided prior to the over twister, a plastic working device applying plastic working to said twisted wire,
It is characterized by providing.

  In the apparatus for manufacturing a steel cord for reinforcing rubber according to the present invention, the plastic working apparatus may include a plurality of rollers arranged in a staggered pattern. Moreover, in the manufacturing apparatus of the steel cord for rubber reinforcement of this invention, it is more preferable to provide a straightener roll after the over twister in the moving path of the stranded wire.

  The method of manufacturing a steel cord for reinforcing rubber according to the present invention is a method for reinforcing a rubber, in which a plurality of strands or cords are manufactured by a buncher-type twisting machine and then twisted with an over twister. In the steel cord manufacturing method, the twisted wire is plastically processed by a plastic processing device before the twisting by the over twister in the moving path downstream of the twisted wire manufactured by the buncher type twisting machine. It is characterized by.

  In the method for producing a steel cord for reinforcing rubber according to the present invention, particularly when the stranded wire produced by the buncher type stranded wire machine is a three-layer stranded strand consisting of a core layer and two sheath layers. An excellent effect can be obtained.

  According to the present invention, by applying plastic processing to the stranded wire in the stranded wire moving path before the over twister, it is possible to reduce the molding rate of the outermost layer filament of the stranded wire. Thereby, generation | occurrence | production of the twist defect by the swelling of the outermost layer filament can be suppressed.

It is a schematic diagram of the manufacturing apparatus of the steel cord for rubber reinforcement of one embodiment of the present invention. It is a schematic diagram of the apparatus which manufactures the three-layer twisted strand wire of one Embodiment of this invention. It is a graph which shows the shaping | molding rate of the outermost layer filament after an over twister. It is a graph which shows the torsion after an over twister. It is a graph which shows the swelling judgment value of the outermost layer filament after an over twister. It is a graph which shows the relationship between the shaping | molding rate of the outermost layer filament after an over twister, and torsion. It is a graph which shows the shaping | molding rate of the outermost layer filament of the code | cord | chord which used the straightener roll after the over twister. It is a graph which shows the torsion of the code | cord | chord which used the straightener roll after the over twister. It is a graph which shows the bulging judgment value of the outermost layer filament of the code | cord | chord which used the straightener roll after the over twister.

Hereinafter, embodiments of a manufacturing apparatus and a manufacturing method of a steel cord for rubber reinforcement of the present invention will be specifically described with reference to the drawings.
In the schematic view of the rubber-reinforcing steel cord manufacturing apparatus 1 according to one embodiment of the present invention shown in FIG. 1, the buncher type twister 10 shows an example of a double twist buncher type twister. The buncher type twisted wire machine 10 includes an arcuate fryer 11 that turns around both ends of the rotating shaft, and guide rolls 12a and 12b provided near both ends of the fryer 11, respectively. 11, the filaments guided in the order of the guide roll 12b are twisted together by turning the fryer 11 to produce a stranded wire c. In the present embodiment, the buncher type twisted wire machine 10 is used to manufacture a layered twisted wire c. The twisted wire c is overtwisted by an over twister 13 made of a pair of rollers provided inside the buncher type twisted wire machine 10, so that twisting direction plastic processing is introduced into the twisted wire c, and the torsion Is suppressed.

  The rubber-reinforcing steel cord manufacturing apparatus 1 according to the present embodiment is a plastic processing apparatus that applies plastic processing to the stranded wire c before the over twister 13 in the downstream stranded wire movement path of the buncher type twisting machine 10. 14 is provided.

  By applying plastic processing to the twisted wire before the twist processing by the over twister 13 is performed by the plastic processing device 14, plastic processing is applied to the outermost layer filament in the stranded wire c of the layer twist, and the molding rate is increased. Can be reduced. The inventor has found that there is a correlation between the outermost layer filament bulge of the stranded wire and the molding rate of the outermost layer filament, and the higher the molding rate, the higher the risk of the bulging of the outermost layer filament of the stranded wire occurring. . Therefore, according to the present embodiment, the outermost filament bulge of the stranded wire is suppressed by applying plastic working to the stranded wire before being twisted by the over twister 13 and reducing the molding rate of the outermost filament. be able to.

  Further, by applying plastic working to the stranded wire c with the plastic working device 14 and performing twisting with the over twister 13, it is possible to achieve a high level of suppression of the molding rate of the outermost filament and suppression of the torsion. Can be made. More specifically, the torsion has a correlation with the rotational speed of the over twister, and the rotational speed of the over twist necessary to obtain desired torsion characteristics is determined by the material of the stranded wire, the cord structure, and the like. The moldability of the outermost layer filament can also be lowered by lowering the rotation speed of the over twister. Therefore, in the case where plastic processing is not applied to the stranded wire before the over twister in the prior art, the torsional characteristics are deteriorated although the molding rate can be lowered by reducing the rotational speed of the over twister. On the other hand, the molding rate of the outermost filament was not good at the rotation speed of the over twister with good torsion characteristics. On the other hand, according to the present invention, the torsion processing is performed by the over twister 13 after plastic processing is performed on the stranded wire c by the plastic processing device 14, thereby providing good torsion characteristics and a low outermost layer filament molding rate. Therefore, it is possible to achieve a high level of compatibility with the suppression of twisting failure due to the outermost filament bulging of the stranded wire.

  In addition, Patent Document 1 describes that a bending process is performed on a twisted cord after a stranded wire process by a group of straightening rolls with respect to a method for manufacturing a steel cord for reinforcing rubber articles. It is only a statement of applicability that it can be applied. In addition, Patent Document 1 does not describe that the outermost filament bulge of the stranded wire can be suppressed by performing plastic working by the plastic working device 14 on the stranded wire c according to the present invention. It also does not describe that suppression of bulging of the outermost filament of the stranded wire and suppression of torsion can be achieved at a high level by overtwisting with an over twister after the plastic working.

  The plastic working device 14 is not particularly limited as long as it is a device capable of applying plastic working to the stranded wire c, but includes a plurality of rollers arranged in a staggered manner as illustrated as an example. Thus, the plastic working device 14 for bending the stranded wire c passing between these rollers can be obtained.

  Moreover, in the apparatus for manufacturing a steel cord for reinforcing rubber according to the embodiment of the present invention, the straightener roll 15 can be provided in the stranded wire moving path after the over twister 13. By providing the straightener roll 15, not only the straightness of the stranded wire c can be improved, but also the moldability of the outermost layer filament of the stranded wire c can be further reduced. Therefore, suppression of the bulging of the outermost filament of the stranded wire and suppression of torsion can be achieved at a higher level.

  The stranded wire c whose straightness is improved by the straightener roll 15 is wound around the spool s through the take-up capstan 16 and the guide roll 17.

  Using the apparatus for manufacturing a steel cord for reinforcing rubber of the present invention, several strands or cords are manufactured by a buncher type twisting machine and then twisted by an over twister before being twisted. In the method of manufacturing a steel cord for reinforcing rubber, in which a twisted wire is subjected to plastic working and then twisted with an over twister on the twisted wire, the twisted wire manufactured by the buncher type twisted wire machine has a core layer and a two-layer sheath It is advantageous that a three-layer twisted stranded wire composed of layers is particularly effective when the production method of the present invention is applied. A schematic diagram of an apparatus for producing such a three-layer stranded wire is shown in FIG.

  In FIG. 2, the buncher-type stranding machine 20 of the rubber-reinforced steel cord manufacturing apparatus 2 includes an arcuate fryer 21 that turns around both ends of the rotating shaft, and guide rolls provided near both ends of the fryer 21. 22a, 22b, an over twister 23, a plastic working device 24, a straightener roll 25, a take-up capstan 26, and a guide roll 27. The configuration of the buncher type twisting machine 20 can be the same as that of the buncher type twisting machine 10 shown in FIG.

  A bobbin bc in which a steel cord c1 obtained by twisting a core filament and a filament of an inner sheath layer is wound to be supplied to the buncher type twisting machine 20, and an outer sheath layer twisted on the steel cord c1. Bobbins b1 to bn around which filaments f1 to fn are wound are prepared. The steel cord c1 and the filaments f1 to fn that are unwound from these bobbins are placed on the moving path of the unwinding tension adjusting device 31 provided corresponding to each of these bobbins bc and b1 to bn and the steel cord c1. After the tension is adjusted by the tension applying device 32 having the provided roller, the tension is applied to the buncher type twisting machine 20.

  When manufacturing a twisted layered wire using the manufacturing apparatus shown in FIG. 2, the plastic processing device 24 applies plastic processing to the twisted wire before the over twister 23, so that the most of the three-layer twisted steel cord can be obtained. Twist failure due to the bulging of the outer filament can be suppressed.

  In manufacturing a steel cord having a 7 × (1 + 6 + 12) +0.25 cord structure used for reinforcing a radial tire for a large construction vehicle, a three-layer twisted steel cord (1 + 6 + 12 × 0.25) used for the strand is used. The rubber reinforcing steel cord manufacturing apparatus shown in FIG. 2 was used.

  As the plastic working device 24 before the over twister 23, there were prepared 13 rollers having a diameter of 25 mm arranged in a staggered pattern and 13 rollers having a diameter of 16 mm arranged in a staggered pattern.

  For the above-described three-layer twisted steel cord after passing through the buncher type twisting machine, the plastic working device 24 and the over twister 23, the outermost layer filament forming ratio, the torsion, and the bulging of the outermost layer filament of the twisted wire with respect to the rotational speed of the over twister The results of examining the judgment values are shown in FIG. 3, FIG. 4 and FIG. 5, respectively, and the relationship between the molding rate of the outermost filament and the torsion is summarized in FIG. In addition, the bulging judgment value of the outermost layer filament of the stranded wire is squeezed with a steel cord with a die, and when the amount of bulging is less than 1.1 times the cord diameter by evaluation of the bulging amount of the outermost layer filament, The case of 1.1 times or more and less than 1.2 times was evaluated as 2, the case of 1.2 times or more and less than 1.3 times was evaluated as 3, and the case of 1.3 times or more was evaluated as 4.

  As can be seen from FIGS. 3 to 5, Example 1 (roller with a diameter of 25 mm) and Example 2 (roller with a diameter of 16 mm) were subjected to plastic working with respect to Comparative Example 1 in which plastic working by the plastic working device 24 was not performed. In both cases, the molding rate of the outermost filament decreased. Further, the rotational speed of the over twister for obtaining a predetermined amount of torsion was lower in Examples 1 and 2 than in Comparative Example 1. Further, as can be seen from FIG. 6, the outermost layer filament molding rate when a predetermined amount of torsion is obtained is lower in Examples 1 and 2 than in the comparative example, and the swell of the outermost layer filament of the stranded wire is suppressed. And torsion suppression were achieved at a high level.

  Next, FIG. 7 shows the result of examining the moldability of the outermost layer filament after using the straightener roll 25 after twisting with an over twister (OT), FIG. 8 shows the result of examining the torsion, and FIG. The results of examining the bulging judgment value of the outermost filament of each are shown in FIG. In these drawings, black circles are obtained by using straightener rolls for the steel cords of Comparative Example 1. A triangle mark uses the straightener roll for the steel cord of Example 1. A rhombus mark uses a straightener roll for the steel cord of Example 2. Further, as the straightener roll after the over twisting, 13 rollers having a diameter of 16 mm, which are arranged in a staggered pattern, were used.

  From these figures, by using the straightener roll 25 after twisting with an over twister, the outermost filament mold forming rate is further reduced, and the rotation speed of the over twister for obtaining a predetermined amount of torsion is reduced. Therefore, the suppression of the bulging of the outermost filament of the stranded wire and the suppression of torsion can be achieved at a higher level.

DESCRIPTION OF SYMBOLS 1, 2: Manufacturing apparatus 10 of the steel cord for rubber reinforcement, 20: Buncher type twisting machine 13, 23: Over twister 14, 24: Plastic processing apparatus 15, 25: Straightener roll

Claims (5)

A buncher type twisting machine that produces twisted wires by twisting together multiple strands,
An over twister that twists the stranded wire produced by this buncher type stranding machine;
And have your downstream movement path of the stranded wire produced by the buncher type stranding machine provided prior to the over twister, a plastic working device applying plastic working to said twisted wire,
An apparatus for manufacturing a steel cord for rubber reinforcement, comprising:   The apparatus for manufacturing a steel cord for rubber reinforcement according to claim 1, wherein the plastic working device includes a plurality of rollers arranged in a staggered pattern. The apparatus for manufacturing a steel cord for rubber reinforcement according to claim 1 or 2, further comprising a straightener roll after an over twister in a moving path of the stranded wire. In the method of manufacturing a steel cord for rubber reinforcement in which a plurality of strands or cords are manufactured by a buncher type twisting machine and then twisted with an over twister on the twisted wires.
For the reinforcement of rubber, wherein the twisted wire is plastically processed by a plastic processing device before the twisting by the over twister in the moving path downstream of the twisted wire manufactured by the buncher type twisted wire machine. Steel cord manufacturing method. The method for producing a steel cord for reinforcing rubber according to claim 4 , wherein the stranded wire produced by the buncher type stranded wire machine is a stranded wire having a three-layer twist from a core layer and two sheath layers.

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